I logged in to messenger, 3 nights back, with a surprise as Ms. Christina threw concerns for her past A-Maths tutees. Technically, it's incorrect of me to address her as Ms. Christina 'cause of her status. However, I would feel weird if I call her by name, which I do to my other more fledged friends, as I still see her as a teacher.
How about Mrs. Christina? Or even Mdm. Christina? Those couldn't fit into my mouth and I just want to be respectful. Anyways, I'm biting my own tongue by giving her a nickname!